Normalizations for the input data (normalization, equalization)
In image process area, the term “normalization“ has many other names such as contrast stretching, histogram stretching or dynamic range expansion etc.
If you have an 8-bit grayscale image, the minimum and maximum pixel values are 50 and 180, we can normalize this image to a larger dynamic range say 0 to 255. After normalize, the previous 50 becomes 0, and 180 becomes 255, the values in the middle will be scaled according to the following formula:
(I_n: new_intensity) = ((I_o: old_intensity)- (I_o_min: old_minimum_intensity)) x ((I_n_max: new_maximum_intensity) - (I_n_min: new_minimum_intensity)) / ((I_o_max: old_maximum_intensity) - (I_o_min: old_minimum_intensity)) + (I_n_min: new_minimum_intensity)